This invention relates to measurement of air flow, and more particularly, to a digital air flow sensor.
Air flow sensors in test and measurement instruments typically require that the measurement instrument be calibrated to the individual sensor element. As such, the sensor is not easily changed in a single instrument nor interchangeable among multiple instruments without recalibration. This increases the cost of manufacturing, and also increases the cost of repair and maintenance of an instrument.
Existing air flow sensors include thermal anemometers with an analog interface between the sensor element and the instrument, thermal anemometers with a digital interface between the sensor element and the instrument using an UART interface, and thermal anemometers using an analog control loop to drive the sensor bridge. However, all these existing sensor configurations have the test and measurement instruments are calibrated to the sensors, and the sensors are not interchangeable between measurement instruments without recalibration.